The nitridation of semiconductor surfaces is used in the manufacture of microelectronic devices for such purposes as providing a passivation layer and/or a thin film insulator. Effort has particularly been directed at processes for forming nitrides of silicon. Silicon nitrides, such as Si.sub.3 N.sub.4, have been formed by processes such as ion implantation or exposure to excited nitrogen at a pressure around 10.sup.-4 Torr combined with thermal annealing at elevated temperatures. However, because of the general lack of reactivity of molecular nitrogen, most studies of silicon nitridation have been performed with the use of more reactive molecules containing nitrogen, such as NH.sub.3 or NO. With ammonia used as the reactive nitrogen source, hydrogen atoms are typically left at the nitride-silicon interface. Furthermore, in many cases, nitridation is obtained only by assisting the process by the use of an electron beam scanned over the surface, by applying unmonochromatized synchrotron radiation ""white light" emitted by a storage ring to the surface, or by thermal annealing at a rather high temperature, e.g., 1000.degree. C. or higher. However, it is found that in the process of forming the nitrides, all of these treatments generally damage the surface and create defects, making subsequent formation of electronic devices difficult or impossible.
It has been determined by applicant that alkali metals are a highly efficient promoter of semiconductor oxidation. Furthermore, it was demonstrated that the alkali metal catalysts are removable from the surface after catalytic oxidation. See P. Soukiassian, et al, "SiO.sub.2 -Si Interface Formation by Catalytic Oxidation Using Alkali Metals and Removal of the Catalyst Species," J. Appl. Phys. 60 (12), 15 December 1986, pp. 4339-4341. The catalytic effects of such alkali metals on silicon and other semiconductor substrates with respect to gases other than oxygen, and particularly nitrogen, has heretofore generally been unknown and unpredicted. In particular the nitrogen molecule (N.sub.2) has a larger dissociation energy than oxygen. Furthermore, it is known that the nitrogen molecule does not stick well on semiconductor surfaces.
It is of great importance that any catalyst used, and alkali metals in particular, not remain at the surface or in the bulk of the silicon or other semiconductor substrate since the presence of the catalyst would render these semiconductors useless for the production of electronic devices. In addition, if high temperature heat treatment or ion bombardment is necessary to remove the catalyst, such treatment will damage the semiconductor surface and partially or totally destroy the usefulness of the semiconductor substrates for formation of microelectronic devices.